Stample: privacybeleid (Engelstalig)

Versie 1.1 (2014/01/31)


In short, Stample stores very little information about its users. We only keep track of the information that is required to let the app function properly. Other than that, users have (limited) options for sharing information with friends, both within Stample and on social media.

This Privacy Policy statement explains in more detail how Stample handles your information. It can be summarized as follows:

  • User data (Section A): Stample only stores basic user information, the stamps that users have collected and traded, and the achievements they have obtained. Passwords are stored securely.
  • Location (Section B): Stample uses your mobile device to see if there are stamps in your vicinity. Your location is temporarily sent to the server during a request, but it is not stored in our database.
  • Stamps (Section C): When you collect a stamp, it is initially visible to you alone. You can choose to share a hint on social media.
  • Achievements (Section D): You obtain achievements based on your Stample activity. Your achievements are automatically visible to your friends. You can also choose to share your achievements on social media.
  • Friends (Section E): You can add friends using their nickname or e-mail address. Your friends can see basic statistics about your Stample activity, including your achievements.
  • Trading (Section F): You can mark a collected stamp as `public', which makes it a candidate for trading. Two Stample friends can randomly exchange the stamps they have marked as `public'.
  • Social media (Section G): You can use Stample to share your achievements on social media, as well as hints about the stamps you've collected. Stample does not do this automatically, unless you allow it.
  • App permissions (Section H): The Stample app requires a number of permissions to function properly. This statement explains how each permission is used.

Finally, secrecy is a key factor for making Stample interesting to use. We deliberately hide the names and locations of our stamps, and we encourage all users to do the same.


A.1 - What information does Stample store about me?

Stample stores the following information on its servers:

  • The fields that you have filled in during registration, including your nickname, e-mail address, password (encrypted), country of residence (if specified), and avatar (if specified).
  • The stamps that you have collected. For each collected stamp, we also store the date and time at which you collected it, and the personal color that you have attached to it.
  • The stamps that you are publicly offering to your Stample friends.
  • All trade actions that you have performed in the past.
  • The achievements that you have obtained.

A.2 - How is my password treated?

When you enter a password (when logging in or registering), Stample immediately encrypts it. Our servers only store this encrypted version of your password. One implication is that we cannot obtain or recover your original password if you lose it. Instead, you can request a password reset on Stample's login screen. You will then receive an e-mail message with further instructions for creating a new password.

A.3 - Can Stample share my personal information with others?

  • Within the Stample app, you can choose to have your nickname, avatar, and score displayed on our website (e.g. for our online leaderboards). This is completely optional.
  • Some information about your account and activity is visible to your Stample friends. (See Section E.)
  • Other user information (such as your e-mail address) is not made public and is not shared with third parties.


B.1 - Does Stample keep track of my location?

Stample only keeps track of your location within the app itself, using the location services of your mobile device. The app periodically checks if there are any stamps in your vicinity for you to collect, by sending a request (including your current location) to our servers. This location is only used for handling the request; it is not stored in our database. Likewise, our servers do not store the fact that a location request has been handled. Simply put, we do not know where our users are; we only know when and where they have collected a stamp.

B.2 - Can users find out each other's locations through Stample?

No: since we do not store location information on our servers, users cannot track each other's exact locations through Stample.

Your Stample friends can see basic information about your Stample activity (Section E), including the number of stamps you have collected, and the achievements you have obtained. Your achievements may provide hints about your past locations; see Section D.

Naturally, if you choose to share your stamps and achievements on social media (Section G), you implicitly also share hints about your location.


C.1 - Can other people find out which stamps I have collected?

Only if you want them to. By default, if you collect a new stamp, it is visible only to you. There are several options to inform other people about the new stamp:

  • Adding the stamp to your public collection (see Section F on trading). In this case, only your Stample friends may find out about your new stamp, if they decide to trade it for one of their own.
  • Sharing a hint on social media (see Section G). In this case, your Facebook friends (or whoever can see your messages according to your Facebook settings) will be able to see the hint.

These actions are completely optional. You are also allowed to keep your Stample activity to yourself. Apart from this, your achievements may provide hints about the stamps you have collected; see Section D.

C.2 - Can another Stample user take any of my stamps?

Only if you want them to, and they are your Stample friend, and they can give you something in return. See Section F on trading.


D.1 - Can other people find out which achievements I have obtained?

Your Stample friends can always see which achievements you have obtained, and when. Furthermore, you can choose to share your achievements on social media (see Section G).

Your current location is never shared with others (see Section A), but your achievements implicitly provide hints about your past locations. For example, an achievement may give away that you have collected a stamp of a certain type (e.g. a train station) at a certain point in time. However, an achievement never refers to a single particular stamp.


E.1 - Who can add me as a Stample friend, and how?

When another Stample user knows your nickname or e-mail address, they can send you a friend request. If you accept the request, you will be added to each other's friend lists. If you decline the request, the other user will not be notified, but he or she may choose to try again.

E.1 - What information is shared with my Stample friends?

Your friends can see the following information about you:

  • Your nickname and avatar.
  • Your registration date, i.e. the day on which you started using Stample.
  • The number of stamps you have collected, and the combined score of all collected stamps.
  • The achievements you have obtained (see Section D).


F.1 - How can I trade a stamp with another user?

Two users can only trade stamps they have marked as `public'.

A newly collected stamp is private by default, meaning that it is visible to you alone. You can personally control which stamps you would like to give away, by marking them as `public'. Within the Stample app, this can be done in the `Trade' tab, or on the information page of a specific stamp (accessible through the `Collection' and `Stamp map' tabs).

To keep things exciting, your Stample friends cannot directly see which stamps you are offering. They can only see whether or not one of their own public stamps could be traded for one of yours. Then, if user A presses the trade button for user B in the `Trade' tab, two stamp (one per user) are randomly chosen from the public collections of both users. The ownership of these stamps will then be swapped between A and B. The original owners cannot collect the same stamp again within the next 24 hours.

This process is mysterious on purpose. While we cannot forbid you to share information with friends, we strongly believe that secrecy keeps the game interesting.


G.1 - What information can I share on social media using Stample?

Once you have collected a stamp, Stample gives you the option to share the news on your Facebook profile. You can also do this after having collected the stamp, by clicking on the Facebook button on the stamp's information screen.

A stamp message on Facebook contains the stamp's image and a hint for its location. The name and exact location of the stamp are deliberately not shared.

You can also share your achievements on Facebook, by clicking on the Facebook button on the achievement's information screen. In contrast to stamp messages, an achievement message always contains the achievement's image, name, and description. Hence, people could use this information to deduce where you may have been. See Section D for more information.

Naturally, if you choose share your stamps and achievements on social media, you implicitly also share hints about your location.

G.2 - Can Stample post messages on social media on my behalf?

Only if you allow it. In the Stample app preferences, you can choose to automatically share newly collected stamps on Facebook. This option is disabled by default, and only you can enable it.

G.3 - Who can see my social media messages about Stample?

This depends on your Facebook settings. You can personally choose who can see your Stample messages, e.g. only you, your friends, friends of your friends, or everyone.


H.1 - Obtaining your location (coarse and fine)

Stample needs to know your location to find out if there are any stamps in your vicinity. Without location information, the app cannot function.

Mobile devices offer coarse and fine location services. The coarse version is based on mobile networks and access points. The fine version is based on GPS and requires more power. To minimize battery consumption, Stample only switches to fine location updates when a stamp is nearby.

See Section A for more information on how your location is used.

H.2 - Accessing the device storage (SD card)

To prevent multiple downloads of the same online resources, Stample stores images of stamps and avatars on your device's SD card or hard drive whenever possible. This minimizes mobile data transfers.

H.3 - Reading your Google Services configuration

To display your stamp collection on an interactive map, Stample uses Google Maps, which in turn uses Google Play Services. Modern Android devices have this feature enabled by default.

H.4 - Network communication

Most of Stample's functionality is based on web requests. Hence, it requires continuous internet access to function properly. Using Wi-Fi only is most likely not sufficient, as most of your Stample activity will take place `in the field' where a Wi-Fi connection is not available. Hence, we recommend enabling mobile internet connections.

Note that you are personally responsible for not exceeding your mobile data limit. Stample's data transfers are minimal. Furthermore, Stample uses your device's storage (SD card) to prevent multiple downloads of the same resources.

H.5 - Running at device startup

You can choose to launch Stample automatically when you start up your phone. This option can be set in the Stample settings menu. If you do not enable it, then you must start Stample manually whenever you restart your device.

H.6 - Vibration

Some notifications and in-app sounds also use the phone's vibration functionality. (Vibrations will not occur if your phone is in silent mode.)


If you have any questions regarding our privacy policy, or if you believe that crucial information is missing from this statement, feel free to e-mail us at